Are you finished with Batman: Arkham Asylum? No, you’re not.

You may have reached the ending. You may have solved all the riddles and collected all the items. You may have visited every room and unlocked every character bio. Until you’ve read this article, however, you won’t fully grasp what those things mean. You won’t fully comprehend all of the game’s geeky tributes and intricate connections. You won’t fully appreciate how much loving fan service Arkham Asylum truly has to offer.

We’ll help you. We’ve done the research. We didn’t just scan these characters’ items and move on… we dug into their histories, learned their trivia and discovered why Arkham Asylum’s developers chose to include them. Plus, we’ll reveal the identity of the Spirit of Arkham, “Mad Dog” and the mystery one-armed inmate. Shall we begin?

Ra’s al Ghul

First comic appearance: Batman #232 (June 1971)

Arkham Asylum appearance: Arkham Mansion (Dr. Young’s Office)

The connection: What’s this? A Batman villain that actually stays dead? Don’t be so naive. Ra’s al Ghul is anywhere between 450 and 700 years old, according to the comics, and capable of replenishing his life – as well as decreasing his physical age – through the use of unique chemical pools. A mere body bag and toe tag aren’t going to keep this international terrorist from his goal of decimating the human population.

Sure enough, when you return to this room at the end of the game, his corpse is gone… most likely stolen by his loyal and secretive followers, the League of Assassins. He’ll be alive again in no time.

Bizarro Fun Fact: Batman’s recently revealed son, Damian Wayne, is also Ra’s al Ghul’s grandson. Family reunions are… interesting.

Two-Face

First comic appearance: Detective Comics #66 (August 1942)

Arkham Asylum appearance: Penitentiary (Controlled Access); Arkham North (Guard House)

The connection: Two-Face wasn’t always the bad guy. As anyone who’s ever read a Batman comic or seen a Batman film already knows, he used to be a heroic district attorney to Gotham City, a staunch ally to the Dark Knight and a close personal friend to Bruce Wayne. Until half his visage was horribly scarred and his schizophrenic personality disorder was triggered, he was just Harvey Dent.

In Arkham Asylum, you’ll discover two rooms plastered with “Vote Dent” posters and buttons. One is a cell, which could belong to Two-Face (though the audio at the end of the game confirms he’s since escaped). The other, however, is a guard room. Do the employees here have a twisted sense of humor? Or is Harvey Dent’s election and subsequent downfall still a recent event in this universe? We may find out in a sequel.

Bizarro Fun Fact: “Two-Face” hasn’t always referred to Harvey Dent. At least five other men have temporarily held the mantle, including a small-time criminal, an actor wearing makeup and Batman himself.

The Penguin

First comic appearance: Detective Comics #58 (December 1941)

Arkham Asylum appearance: Intensive Treatment (Transfer Loop); Arkham Mansion (South Corridor)

The connection: The Penguin character is defined by two main traits. First, his use of modified umbrellas as gimmicky weaponry; they can double as anything from guns and knives to lasers and helicopter blades in his pudgy little hands. Who knows what special powers the set in Arkham Mansion hide?

Second, in most storylines, the Penguin is not an insane villain. He’s a wealthy entrepreneur and highbrow society man who runs underground criminal rings through the façade of his Iceberg Lounge… a club that Batman tolerates in order to collect information. Until Danny DeVito’s film portrayal in Batman Returns, the Penguin wasn’t even deformed. If the poster above is any indication, Arkham Asylum’s developers have opted for the classic, gentlemanly, non-monster version as well.

Bizarro Fun Fact: Alfred, loyal butler to the Wayne dynasty, was once a servant of the Cobblepots, Penguin’s family.

Catwoman

First comic appearance: Batman #1 (Spring 1940)

Arkham Asylum appearance: Arkham Mansion (East Wing Corridor)

The connection: Batman inhabits a relatively testosterone-dominated universe, full of male villains, male allies and (young) male sidekicks. So when the rare female character shows up, you know the writers and artists are going to go a little overboard with her.

Such is the case with Catwoman’s ever-changing costume. In her first appearance, she didn’t have one, but since then, she’s worn whiskered cat masks, hoods with cat ears, attached cat tails and skintight catsuits in colors as diverse as purple, green, black and grey. Many iterations have included retractable cat claws like the ones pictured above, and the 2000s Catwoman added infrared goggles to aid in her high-tech, high-stakes thievery. If she appears in a future game, expect this modern interpretation.

Bizarro Fun Fact: Catwoman uses a whip because the weapon requires extensive training. If a random enemy were to knock it from her grip, he would be unable to turn it against her.

Mr. Freeze

First comic appearance: Batman #121 (February 1959)

Arkham Asylum appearance: Penitentiary (Extreme Incarceration)

The connection: That ice is much more than a visual gag. Dr. Victor Fries, a scientist experimenting with cryogenics to save his terminally ill wife, was accidentally exposed to his own chemicals and now, thanks to an abnormally low body temperature, requires refrigeration to survive. Usually, the bubble-headed suit provides this protection, but the police obviously can’t afford to let him keep that in custody. Thus, the custom-made, frozen prison cell.

Bizarro Fun Fact: Mr. Freeze was originally Mr. Zero. His name was changed for the 1960s television series.